The present invention relates to a device for displaying a series of advertisements in a display window.
Various display devices of the aforementioned type are already known. One of these presents a prismatic support normally fitted with an advertisement on each face, and which is rotated in steps so as to display one face at a time at the display window. A major drawback of this type of device is that it requires the use of large-size prisms, and provides for displaying only a limited number of advertisements, any increase in which involves frequent replacement of the prism.
To reduce the size of the system, the advertisements of another known device, widely used in sports stadiums, are divided into a number of rectangular portions, each fitted to a respective prism. Such a device presents several drawbacks, in that it requires a highly complex mechanism for simultaneously rotating all the prisms; provides for poor quality display, by virtue of the image being split noticeably by horizontal and vertical lines; and, as in the previous case, provides for displaying only a limited number of advertisements, replacement of which, however, in this case is even more complex.
A further device is also known in which the advertisements are carried on a flexible strip which is wound and unwound between two parallel rollers on either side of the display window. The two rollers are rotated by a single motor and two chains engaging two pulleys, each connected to the respective roller by a respective idle wheel, so that the device is invariably noisy due to idling of the wheels.